Method of grouping user devices

ABSTRACT

A grouping method of user devices comprises configuring one or more codes for each of the user devices by a base station wherein each of said one or more codes corresponds to a delay tolerance, performing a grouping task by the base station according to the delay tolerances and a determining result of channel-usage demand corresponding to each of the user devices so as to form one or more first-type groups and one or more second-type groups wherein each first-type group corresponds to a first-group delay tolerance and each second-type group corresponds to a second-group delay tolerance, and performing a selection from user devices in the first-type groups and the second-type groups to form one or more target groups by the base station according to the first-group delay tolerances and the second-group delay tolerances.

BACKGROUND 1. Technical Field

This invention relates to a grouping method of user devices.

2. Related Art

In the field of long term evolution (LTE) network, for improving thespectrum usage efficiency and providing the better service quality forthe user end, the network end usually has to measure and report wirelesschannels. The base station can allocate the related parameters of userdevices, so as to improve the usage efficiency of channel resources.

In general, a base station is connected with multiple user devices, andthe parameter characteristics, such as delay tolerance, of these userdevices may vary. When the number of the user devices is large, the basestation cannot easily configure the parameters of these user devices forimproving the usage efficiency of channel resources due to thedifferences in the parameter characteristics.

SUMMARY

According to an embodiment of this invention, a grouping method of userdevices comprises configuring one or more codes for each of the userdevices by a base station, wherein each of said one or more codescorresponds to a delay tolerance; performing a grouping task by the basestation according to the delay tolerances and a determining result ofchannel-usage demand corresponding to each of the user devices so as toform one or more first-type groups and one or more second-type groups,wherein each first-type group corresponds to a first-group delaytolerance and each second-type group corresponds to a second-group delaytolerance; and performing a selection from user devices in thefirst-type groups and the second-type groups to form one or more targetgroups by the base station according to the first-group delay tolerancesand the second-group delay tolerances.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of long term evolution network architectureaccording to an embodiment of this invention.

FIG. 2 is a flow chart of a grouping method of user devices according toan embodiment of this invention.

FIG. 3 is a detailed flow chart of a grouping method of user devicesaccording to another embodiment of this invention.

FIG. 4 is a schematic diagram of initial grouping according to anembodiment of this invention.

FIG. 5 is a schematic diagram of grouping according to an embodiment ofthis invention.

FIG. 6 is a schematic diagram of target groups according to anembodiment of this invention.

FIG. 7A is an initial setting waveform diagram of the user devicesaccording to an embodiment of this invention.

FIG. 7B is an actual operating waveform diagram of the user devicesaccording to an embodiment of this invention.

FIG. 8A is an initial setting waveform diagram of the user devicesaccording to another embodiment of this invention.

FIG. 8B is an actual operating waveform diagram of the user devicesaccording to another embodiment of this invention.

DETAILED DESCRIPTION

In the following detailed description, for purposes of explanation,numerous specific details are set forth in order to provide a thoroughunderstanding of the disclosed embodiments. It will be apparent,however, that one or more embodiments may be practiced without thesespecific details. In other instances, well-known structures and devicesare schematically shown in order to simplify the drawings.

Please refer to FIG. 1 and FIG. 2, wherein FIG. 1 is a block diagram oflong term evolution network architecture according to an embodiment ofthis invention, and FIG. 2 is a flow chart of a grouping method of userdevices according to an embodiment of this invention. As shown in FIG.1, the long term evolution network architecture comprises a base stationeNB and user devices 1-8. The base station eNB has communicationconnections with the user device 1-8. In practice, the base station eNBis provided with a radio resource control (RRC) layer and a media accesscontrol (MAC) layer, and the base station eNB can have a schedulerdisposed at the media access control (MAC) layer. The radio resourcecontrol (RRC) layer of the base station eNB can be configured to set thechannel-state information (CSI) report parameter, the discontinuousreception (DRX) parameter and so on of the user devices.

As shown in the procedure of the grouping method in Fig., in step S201,the base station eNB configures one or more codes of each of the userdevices 1-8, wherein each code corresponds to a delay tolerance. In stepS202, the base station eNB performs a grouping task according to thedelay tolerances and a determining result of channel-usage demandcorresponding to each of the user devices, so as to form one or morefirst-type groups and one or more second-type groups, wherein eachfirst-type group corresponds to a first-group delay tolerance and eachsecond-type group corresponds to a second-group delay tolerance.

In an embodiment, said step S201 comprises configuring said one or morecodes of the user devices according to the service type of each of theuser devices. The service type can be voice/video transmission,interactive games, mail/community communication, file sharing, etc., andare not enumerated one by one herein.

In step S203, the base station eNB performs a selection from the userdevices in the first-type groups and the second-type groups to form oneor more target groups according to the first-group delay tolerances andthe second-group delay tolerances.

In an embodiment, the grouping method of this invention furthercomprises step S204, wherein the base station eNB determines whether tosplit at least one of the target groups according to the sum ofchannel-usage demand values of the user devices in each target group.

For the further explanation of the grouping method of this invention,please refer to FIG. 3 and Table 1, wherein FIG. 3 is a detailed flowchart of a grouping method of user devices according to anotherembodiment of this invention, and Table 1 is a lookup table according toan embodiment of this invention. In the delay tolerance Dp,i describedin the following example, p represents a code, and i represents thenumber of a user device (such as number 1-8 in FIG. 1). The procedure ofsteps S301-S304 in FIG. 3 is approximately similar to that of stepsS201-204 in FIG. 2, except that step S302 in FIG. 3 comprises sub-stepsS3021-3023 and step S304 comprises sub-steps S3041-3042.

As shown in FIG. 3, firstly in step S301, the base station eNBconfigures one or more codes for each of user device 1-8, such as codes1-9 as shown in Table 1, and each of the codes corresponds to a delaytolerance.

In sub-step S3021 of step S302, the base station eNB divides the userdevices into one or more initial first-type groups and one or moreinitial second-type groups according to the delay tolerances. In anembodiment, the sub-step S3021 comprises by the base station eNB,selecting the user devices having the identical minimum delay tolerancefrom the user device 1-8 to form said one or more initial first-typegroups, and by the base station eNB, selecting the user devices havingthe identical maximum delay tolerance from the user device 1-8 to formsaid one or more initial second-type groups. A practical example isillustrated in the following.

TABLE 1 Code Delay tolerance (ms) Service type 2 100 TP1 4 150 TP2 3 50TP3 5 300 TP4 1 100 TP5 6 300 TP6 7 100 TP7 8 300 TP8 9 300 TP9

In this example, user device 1 providing service types TP1, TP2, TP6 hasdelay tolerance D2,1 which is 100 ms, delay tolerance D4,1 which is 150ms and delay tolerance D6,1 which is 300 ms. The user device 2 providingservice types TP2, TP3, TP7 has delay tolerance D4,2 which is 150 ms,delay tolerance D3,2 which is 50 ms and delay tolerance D7,2 which is100 ms. The user device 3 providing service types TP2, TP8 has delaytolerance D4,3 which is 150 ms and delay tolerance D8,3 which is 300 ms.The user device 4 providing service types TP1, TP2, TP9 has delaytolerance D2,4 which is 100 ms, delay tolerance D4,4 which is 150 ms anddelay tolerance D9,4 which is 300 ms. The user device 5 providingservice types TP2, TP3 has delay tolerance D4,5 which is 150 ms anddelay tolerance D3,5 which is 50 ms. The user device 6 providing servicetypes TP3, TP7 has delay tolerance D3,6 which is 50 ms and delaytolerance D7,5 which is 100 ms. The user device 7 providing servicetypes TP3, TP5 has delay tolerance D3,7 which is 50 ms and delaytolerance D1,7 which is 100 ms. The user device 8 providing servicetypes TP2, TP3 has delay tolerance D4,8 which is 150 ms and delaytolerance D3,8 which is 50 ms.

Please further refer to Table 2 and FIG. 4, wherein Table. 2 is aclassification table of delay tolerances of user devices according to anembodiment of this invention, and FIG. 4 is a schematic diagram ofinitial grouping according to an embodiment of this invention. Based onthe aforementioned example, as shown in Table 2 and FIG. 4, the userdevices 1, 4 have the identical minimum delay tolerance 100 ms, so thatthe base station eNB classified the user devices 1, 4 as an initialfirst-type group Gm1. The user device 3 having the minimum delaytolerance 150 ms is individually classified as another initialfirst-type group Gm2 by the base station eNB. The user device 2, 5, 6,7, 8 have the identical minimum delay tolerance 50 ms, so that the basestation eNB classifies the user devices 2, 5, 6, 7, 8 as yet anotherinitial first-type group Gm3. In this embodiments, the first-group delaytolerance corresponding to the initial first-type group Gm1 is 100 ms,the first-group delay tolerance corresponding to the initial first-typegroup Gm2 is 150 ms, and the first-group delay tolerance correspondingto the initial first-type group Gm3 is 50 ms.

On the other hand, the user devices 1, 3, 4 have the identical maximumdelay tolerance 300 ms, so that the base station eNB classifies the userdevices 1, 3, 4 as an initial second-type group Gl1. The user devices 2,5, 8 have the identical maximum delay tolerance 150 ms, so that the basestation eNB classifies the user devices 2, 5, 8 as another initialsecond-type group Gl2. The user devices 6, 7 have the identical maximumdelay tolerance 100 ms, so that the base station eNB classifies the userdevices 6, 7 as yet another initial second-type group Gl3. In thisembodiments, the second-group delay tolerance corresponding to theinitial second-type group Gl1 is 300 ms, the second-group delaytolerance corresponding to the initial second-type group Gl2 is 150 ms,and the second-group delay tolerance corresponding to the initialsecond-type group Gl3 is 100 ms.

TABLE 2 User device 1 300 ms, 150 ms, 100 ms User device 2 150 ms, 100ms, 50 ms User device 3 300 ms, 150 ms User device 4 300 ms, 150 ms, 100ms User device 5 150 ms, 50 ms User device 6 100 ms, 50 ms User device 7100 ms, 50 ms User device 8 150 ms, 50 ms

In step S3022, the base station eNB determines whether each of the userdevices in each of the initial second-type groups has the channel-usagedemand (traffic demand) to selectively remove at least one of the userdevices from this initial second-type group, so as to form one or moresecond-type groups. In an embodiment, said step S3022 comprises when thebase station eNB determines that at least one of the user devices in oneof the initial second-type groups has the channel-usage demand, removingthis user device from this initial second-type group by the base stationeNB, so as to form one or more second-type groups.

In step S3023, the base station eNB determines whether each of the userdevices in each of the initial first-type groups has the channel-usagedemand to selectively remove at least one of the user devices from thisinitial first-type group, so as to form one or more first-type groups.In an embodiment, said step S204 comprises when the base station eNBdetermines that at least one of the user devices in one of the initialfirst-type groups does not have the channel-usage demand, removing thisuser device from this initial second-type group by the base station eNB,so as to form one or more second-type groups.

More particularly, the code of a user device corresponds to a normalizedchannel-usage demand. When a user device has a normalized channel-usagedemand Rp,i, wherein p represents a code, and i represents the number ofthe user device (such as number 1-8 in FIG. 1), in practice, the methodof determining whether the user device has the channel-usage demand isas follows: when Σ_(p=1) ^(p=p)Rp,i>0, the user device has thechannel-usage demand. On the contrary, when Σ_(p=1) ^(p=p)Rp,i=0, theuser device does not have the channel-usage demand.

Based on the aforementioned examples, when the user devices 1, 3, 5, 7have the channel-usage demand, and the other user devices 2, 4, 6, 8does not have channel-usage demand. At this moment, the base station eNBmakes the user devices 1, 3 in the initial second-type group Gl1 beremoved from the initial second-type group Gl1, makes the user device 5in the initial second-type group Gl2 be removed from the initialsecond-type group Gl2, and makes the user device 7 in the initialsecond-type group Gl3 be removed from the initial second-type group Gl3.On the other hand, the base station eNB makes the user device 4 in theinitial first-type group Gm1 be removed from the initial first-typegroup Gm1, and makes the user devices 2, 6, 8 in the initial first-typegroup Gm3 be removed from the initial first-type group Gm3.

In the aforementioned embodiments, the base station eNB performs theinitial grouping according to the maximum delay tolerances and theminimum delay tolerances of the user devices, and then determineswhether each of the user devices has channel-usage demand to remove partof the user devices one by one. In another embodiment, the base stationeNB can firstly determine whether each of the user devices has thechannel-usage demand, and then perform the grouping according to themaximum delay tolerances and the minimum delay tolerances of the userdevices and remove part of the user devices according to the determiningresult of the channel-usage demand. In other words, this invention isnot limited to the order of the maximum and minimum delay tolerancegrouping step and the channel-usage demand determining step shown instep S302 of FIG. 3.

Please further refer to FIG. 5, wherein FIG. 5 is a schematic diagram ofgrouping according to an embodiment of this invention. After removingthe specific user device according to the channel-usage demand by thebase station eNB as aforementioned, the obtained grouping state of theuser devices as shown in FIG. 5. In other words, after performing theaforementioned grouping task, the first-type groups Gm1′-Gm3′ and thesecond-type groups Gl1′-Gl3′ can be formed finally as shown in FIG. 5.Afterwards, the base station eNB can further form one or more targetgroups according to this grouping state.

More specifically, as shown in step S303, the base station eNB performsa selection from the user devices in the first-type groups and thesecond-type groups to form one or more target groups according to thefirst-group delay tolerances and the second-group delay tolerances. Inan embodiment, said step S303 comprises when the base station eNBdetermines that one of the first-group delay tolerances is identical toone of the second-group delay tolerances, selecting the user devices inthe first-type group corresponding to this first-group delay toleranceand the user devices in the second-type group corresponding to thissecond-group delay tolerance to form said target group.

More particularly, please further refer to FIG. 6, wherein FIG. 6 is aschematic diagram of target groups according to an embodiment of thisinvention. In FIG. 5, since the second-group delay tolerancecorresponding to the second-type group Gl2′ is 150 ms, and thefirst-group delay tolerance corresponding to the first-type group Gm2′is also 150 ms, the base station eNB can select the user devices 2, 8from the second-type group Gl2′ and the user device 3 from thefirst-type group Gm2′ to form a target group Gk1, as shown in FIG. 5. Onthe other hand, since the second-group delay tolerance corresponding tothe second-type group Gl3′ is 100 ms, and the first-group delaytolerance corresponding to the first-type group Gm1′ is also 100 ms, thebase station eNB can select the user device 6 from the second-type groupGl3′ and the user device 1 from the first-type group Gm1′ to from atarget group Gk2, as shown in FIG. 6.

Afterwards, in sub-step S3041 of step S304, the base station eNBdetermines whether the sum of the normalized channel-usage demand valuesof the user devices in any one of the target groups is larger than 1,and in sub-step S3042, when the sum of the normalized channel-usagedemand values of the user devices in any one of the target groups islarger than 1, the base station eNB splits this target group.

Explained by the target group Gk1 in the embodiment of FIG. 6, thenormalized channel-usage demand R2 of the user device 2 is assumed to be0.2, the normalized channel-usage demand R3 of the user device 3 is 0.3,the normalized channel-usage demand R8 of the user device 8 is 0.7. Inthis case, the base station eNB determines that the sum of thenormalized channel-usage demand values of the user devices in the targetgroup Gk1 is larger than 1, so that it should split this target groupGk1. The aforementioned normalized channel-usage demand value can becalculated by Σ_(p=1) ^(p=p)R_(p,i).

In an embodiment, the split performed on this target group by the basestation eNB comprises by the base station eNB, selecting the user devicehaving the maximum normalized channel-usage demand value from the targetgroup to form another group other than the target groups. Explained bythe aforementioned example, since the user device 8 has the maximumchannel-usage demand value, the base station eNB selects the user device8 to be out of the target group Gk1 to form another target group Gk3(not shown in the figure). The aforementioned splitting method of thetarget group is merely illustrative and the invention is not limitedthereto. In practice, after completing sub-step S3042, the sub-stepS3041 is repeated to perform the determining until the sum of thenormalized channel-usage demand values of the user devices in everytarget group is less than 1. In other words, when the base station eNBdetermines that the sum of the normalized channel-usage demand values ofthe internal user devices in every target group is less or equal to 1,this grouping method is ended.

In practice, after completing the aforementioned grouping of the targetgroups, the base station eNB can further assign different physicaluplink control channel resources to different target groups, and performallocation of channel-state report resources on the user devices in thesame target group. In the following, the allocation of channel-statereport resources for the user devices in a single target group isdescribed.

In an embodiment, the grouping method provided in this invention furthercomprises: by the base station eNB, respectively sending radio resourcecontrol (RRC) configuration messages to the user devices in one of thetarget groups. The RRC configuration message comprises a periodicchannel-state information report parameter and a discontinuous receptionparameter, wherein the periodic channel-state information reportparameter comprises a report period, a report time offset and physicaluplink control channel (PUCCH) resource information; when the basestation eNB predicts that conflicting user devices in the user devicesin the target group are going to simultaneously perform channel-stateinformation reporting according to the operational states of the userdevices, the base station eNB decides one of the conflicting userdevices to perform the channel-state information reporting, and sends asleep instruction to other conflicting user devices other than theconflicting user device which is allowed to perform the channel-stateinformation reporting. The RRC configuration messages which are sent tothe user devices comprise the identical report period, the identicalreport time offset and the identical PUCCH source information. The sleepinstruction can be a discontinuous receiving command media accesscontrol layer control unit (DRX Command of MAC CONTROL ELEMENT, DRX CE),but is not limited to this.

Using the target group GK2 as a practical example to illustrate theabove embodiment, please refer to FIG. 1, FIG. 6, FIG. 7A and FIG. 7B,wherein FIG. 7A is an initial setting waveform diagram of the userdevices according to an embodiment of this invention, and FIG. 7B is anactual operating waveform diagram of the user devices according to anembodiment of this invention. The base station eNB respectively sendsthe radio resource control (RRC) configuration messages to the userdevice 1 and the user device 6. As shown in the initial setting waveformdiagram of FIG. 7A, the discontinuous reception parameter DRX1configured to the user device 1 comprises a discontinuous receptionperiod P1, a wake-up time shift SD1 and wake-up duration TD1, and thediscontinuous reception parameter DRX2 configured to the user device 6comprises a discontinuous reception period P2, a wake-up time shift SD2and wake-up duration TD2.

The wake-up duration and sleep duration are repeatedly presented in aperiodic manner and staggered to form a power-saving mechanism ofdiscontinuous reception. In this embodiments, the user device 1 and theuser device 6 are configured with the identical report period (e.g. C1shown in FIG. 7A), the identical report time offset (e.g. SC shown inFIG. 7A) and the identical PUCCH resource (e.g. CSI1 shown in FIG. 7A).After completing the aforementioned parameter configuration of the userdevice 1 and the user device 6, the base station eNB further predictsthat the user device 1 and the user device 6 in the target group Gk2 aregoing to simultaneously perform channel-state information reportingaccording to the operational states of the user device 1 and the userdevice 6. At this moment, the base station eNB determines that the userdevice 1 and the user device 6 are conflicting user devices.

More particularly, as shown in the actual operating waveform diagram ofFIG. 7B, since during the state information report time t1, the userdevice 1 and the user device 6 are both in an active state ON, the basestation eNB determines that a channel-state information reportingconflict will occur between the user device 1 and the user device 6;thus, the base station eNB can decide one of the two user devices toperform the channel-state information reporting according to datatransmission states of the user device 1 and the user device 6, and theother one of the two user devices receives a sleep instruction from thebase station eNB so as to enter an inactive state OFF. The sleepinstruction can be a discontinuous receiving command media accesscontrol layer control unit (DRX Command of MAC CONTROL ELEMENT, DRX CE),but is not limited to this.

In the embodiment of FIG. 7B, if the user device 1 will perform datatransmission but the user device 6 would not perform data transmission,the base station eNB decides the user device 1 to perform channel-stateinformation reporting, and sends a sleep instruction to the user device6 to force it into a dormant state (i.e. inactive state OFF). By theaforementioned method, the channel-state information reporting conflictbetween the user device 1 and the user device 6 may be avoided, so thatthe PUCCH resource sharing between different user devices in the sametarget group may be achieved. The sleep instruction can be adiscontinuous receiving command media access control layer control unit(DRX Command of MAC CONTROL ELEMENT, DRX CE), but is not limited tothis.

The aforementioned embodiments of FIG. 7A and FIG. 7B mainly uses thesleep instruction sent by the base station eNB to force the user devicewhich does not perform data transmission into the dormant state, so asto dynamically allocate the physical uplink control channel resources tothe user devices for periodic channel-state information reporting, inorder to improve the usage efficiency of the physical uplink controlchannel resources and further reduce the overall demand for the physicaluplink control channel resources. In another embodiment, the abovepurpose may be achieved by configuring a discontinuous reception periodand a state information report period which have a specific periodlength relationship, which will be described in details below. The sleepinstruction can be a discontinuous receiving command media accesscontrol layer control unit (DRX Command of MAC CONTROL ELEMENT, DRX CE),but is not limited to this.

In an embodiment, the grouping method provided in this invention furthercomprises: by the base station eNB, performing a scheduling algorithm toobtain a report period, a report time offset and the discontinuousreception period corresponding to each of the user devices in one of thetarget groups, the wake-up time shift corresponding to each of the userdevices and the wake-up duration corresponding to each of the userdevices, so as to make a wake-up time of each of the user devices notoverlap with a channel report time; by the base station eNB,respectively sending radio resource control (RRC) configuration messagesto the user devices. The RRC configuration message comprises a reportperiod, a report time offset, physical uplink control channel (PUCCH)source information, the discontinuous reception period corresponding tothe user device which receives this RRC configuration message, thewake-up time shift corresponding to the user device which receives thisRRC configuration message, and the wake-up duration corresponding to theuser device which receives this RRC configuration message. The RRCconfiguration messages which are sent to the user devices have theidentical report period, the identical channel report time and theidentical PUCCH resource information.

In the following, the target group GK2 is similarly used as a practicalexample to illustrate the above embodiment. Please refer to FIG. 1, FIG.5, FIG. 8A and FIG. 8B, wherein FIG. 8A is an initial setting waveformdiagram of the user devices according to another embodiment of thisinvention, and FIG. 8B is an actual operating waveform diagram of theuser devices according to another embodiment of this invention. As shownin FIG. 8A, the processor in the base station eNB (not shown in thefigure) firstly performs a scheduling algorithm to obtain a stateinformation report period C2, a report time offset SC, the discontinuousreception periods P1′ and P2′, the wake-up time shifts SD1, SD2 and thewake-up duration TD1 and TD2 corresponding to the user device 1 and theuser device 6.

After obtaining the above parameters, the processor in the base stationeNB further sends RRC configuration messages respectively to the userdevice 1 and the user device 6. The RRC configuration message comprisesa state information report period C2, a report time offset SC and PUCCHresource (e.g. CSI2 shown in FIG. 8A) information. The RRC configurationmessage further comprises the discontinuous reception periods P1′ andP2′ corresponding to the user device 1 and the user device 6, and thewake-up time shift SD1, SD2 and the wake-up duration TD1, TD2corresponding to the user device 1 and the user device 6.

In this embodiments, the discontinuous reception periods P1′ and P2′ areset as twice of the state information report period C2; however, themultiple described herein is merely illustrative and this invention isnot limited thereto. In this embodiments, the user device 1 and the userdevice 6 are configured to have the identical report period C2, theidentical report time (e.g. t2) and the identical PUCCH resource CSI2.

More particularly, a processor in the base station eNB can be configuredto decide one of the user device 1 and the user device 6 to perform datatransmission in the data transmission duration DTP (comprising thewake-up duration TD1 and the extended time interval EP shown in FIG. 8B,for example). When the state information report time of the user deviceperforming data transmission is located in the data transmissionduration DTP, the user device performing the data transmission performschannel-state information reporting, and other user devices except theuser device performing the data transmission do not perform thechannel-state information reporting. The data transmission duration DTPis associated with the wake-up duration TD1. The wake-up duration TD1and TD2 can be used to decide the wake-up times DUP1, DUP2 of the userdevices 1, 6. The wake-up times DUP1, DUP2 and the state informationreport time (e.g. t2) are staggered (i.e. no overlap therebetween).

In the actual operating waveform diagram of FIG. 8B, if the base stationeNB decides the first user device 1 to perform data transmission in thedata transmission duration DTP and the state information report time t2is located in the data transmission duration DTP, the user device 1 usesthe physical uplink control channel resource CSI2 to performchannel-state information reporting. In this case, the second userdevice 6 does not perform the channel-state information reporting. Thestate information report time t2 is decided by the report period C2 andthe report time offset SC, and the data transmission duration DTP isassociated with the discontinuous reception period P1′, the wake-up timeshift SD1 and the wake-up duration TD1. In the actual operating example,as shown in FIGS. 8A and 8B, the base station eNB is configured toextend the wake-up duration TD1 by a time interval EP to generate thedata transmission duration DTP. In other words, when the user device 1transmits data in the wake-up duration TD1, since the wake-up durationTD1 is insufficient, the base station eNB can extend the wake-upduration TD1 by a time interval EP to allow the user device 1 tocontinue to transmit data until the transmission is completed.

In view of the above description, the grouping method of user devicesprovided in this invention, mainly by the base station, performs theinitial grouping on the user devices according to the maximum delaytolerances and the minimum delay tolerances firstly, and then removespart of the user devices from the corresponding type group according tothe channel-usage demand of the user devices. Afterwards, the userdevices having the identical group delay tolerance in these type groupsare selected to form a target group. Finally, the sum of the normalizedchannel-usage demand values of the target group is determined to decidewhether to further split this target group. Thereby, the user devicescan be appropriately classified into different groups, so that the basestation may individually allocate parameters for these user devices in asingle group to improve the channel resource usage efficiency of theuser devices in a single group.

What is claimed is:
 1. A grouping method, applied to user devicesconnected to a base station, comprising: by the base station,configuring one or more codes for each of the user devices, wherein eachof said one or more codes corresponds to a delay tolerance; by the basestation, performing a grouping task according to the delay tolerancesand a determining result of channel-usage demand corresponding to eachof the user devices, so as to form one or more first-type groups and oneor more second-type groups, wherein each of said one or more first-typegroups corresponds to a first-group delay tolerance, and each of saidone or more second-type groups corresponds to a second-group delaytolerance; and by the base station, performing a selection from userdevices in the one or more first-type groups and the one or moresecond-type groups to form one or more target groups according to thefirst-group delay tolerances and the second-group delay tolerances,wherein the delay tolerances of the one or more first-type groups andthe one or more second-type groups are different; wherein by the basestation, performing the grouping task according to the delay tolerancesand the determining result of the channel-usage demand corresponding toeach of the user devices, so as to form said one or more first-typegroups and said one or more second-type groups comprising: by the basestation, dividing the user devices into one or more initial first-typegroup and one or more initial second-type group according to the delaytolerances; by the base station, determining whether each of the userdevices in each of the initial second-type groups has the channel-usagedemand to selectively remove at least one of the user devices from theinitial second-type group so as to form said one or more second-typegroups; and by the base station, determining whether each of the userdevices in each of the initial first-type groups has the channel-usagedemand to selectively remove at least one of the user devices from theinitial first-type group so as to form said one or more first-typegroups.
 2. The grouping method according to claim 1, further comprising:by the base station, determining whether to split at least one of thetarget groups according to a sum of normalized channel-usage demandvalues of user devices in each of the target groups.
 3. The groupingmethod according to claim 2, wherein by the base station, determiningwhether to split said at least one of the target groups according to thesum of the normalized channel-usage demand values of the user devices ineach of the target groups comprising: by the base station, determiningwhether the sum of the normalized channel-usage demand values of theuser devices in any one of the target groups is larger than 1; and whenthe sum of the normalized channel-usage demand values of the userdevices in any one of the target groups is larger than 1, splitting thetarget group by the base station.
 4. The grouping method according toclaim 3, wherein splitting the target group by the station comprises: bythe base station, selecting a user device having a maximum normalizedchannel-usage demand value in the target group to form another targetgroup other than the target groups.
 5. The grouping method according toclaim 1, wherein the base station configures said one or more codes ofeach of the user devices according to service types of the user devices.6. The grouping method according to claim 1, wherein by the basestation, dividing the user devices into said one or more initialfirst-type groups and said one or more initial second-type groupscomprising: by the base station, selecting user devices having identicalminimum delay tolerance from the user devices to form said one or moreinitial first-type groups; by the base station, selecting user deviceshaving identical maximum delay tolerance from the user devices to formsaid one or more initial second-type groups.
 7. The grouping methodaccording to claim 1, wherein by the base station, determining whethereach of the user devices in each of the initial second-type groups hasthe channel-usage demand to selectively remove said at least one of theuser devices from the initial second-type group so as to form said oneor more second-type groups comprising: when the base station determinesthat at least one of the user devices in one of the initial second-typegroups has the channel-usage demand, the base station removes the userdevice from the initial second-type group.
 8. The grouping methodaccording to claim 1, wherein by the base station, determining whethereach of the user devices in each of the initial first-type groups hasthe channel-usage demand to selectively remove said at least one of theuser devices from the initial first-type group so as to form said one ormore first-type groups comprising: when the base station determines thatat least one of the user devices in one of the initial first-type groupsdoes not have the channel-usage demand, the base station removes theuser device from the initial first-type group.
 9. The grouping methodaccording to claim 1, wherein by the base station, forming said one ormore target groups according to the first-group delay tolerances and thesecond-group delay tolerances comprising: when the base stationdetermines that one of the first-group delay tolerances is identical toone of the second-group delay tolerances, selecting the user devices inthe first-type group corresponding to the first-group delay toleranceand the user devices in the second-type group corresponding to thesecond-group delay tolerance to form the target group.
 10. The groupingmethod according to claim 1, wherein by the base station, performing thegrouping task according to the delay tolerances and the determiningresult of the channel-usage demand corresponding to each of the userdevices, so as to form said one or more first-type groups and said oneor more second-type groups comprising: by the base station, determiningwhether each of the user devices has the channel-usage demand; by thebase station, dividing the user devices into one or more initialfirst-type groups and one or more initial second-type groups accordingto the delay tolerances; by the base station, removing a user device nothaving the channel-usage demand from the initial first-type group tofrom said one or more first-type groups; and by the base station,removing a user device having the channel-usage demand from the initialsecond-type group to form said one or more second-type group.